A sad sad day

I did it again.
I was thinking about him, a sick coworker who was always very kind to me; who was on sick leave and still called me a couple months ago saying how he had missed me and how miserable he felt with all the surgeries he had to go though.  I remember how he talked for more than 30 minutes when he called, I remember how lonely and bored and disappointed he sounded.  And how he mentioned that he hoped to see me again but didn't want me to visit him in that condition.
I was thinking just a couple days ago that I had not heard from him for a while, that I needed to find a way to contact him.
And now today I heard that he is passed away!
How stupid to take people's presence as granted and delaying the calls and visits to another day thinking they will wait and the whole universe will wait and all will be always available!  I had done this before too.  I wanted to talk to a colleague one day and I thought I'd do it tomorrow and he died that night. 
Another colleague has sent an email about his wife who needs to go through heart and double lung implant.
A friend's mom is terminally ill.
I suddenly feel so ungrateful for all I have.
He was a great man.  My God bless his soul!